摘要
分布式电源通常采用无互联线的传统"功率–电压–电流"三环下垂控制器来实现并联系统间的功率均分,但采用三环下垂控制不仅控制器复杂,而且其控制效果受连线阻抗阻感比影响严重。尤其是在线路短、阻抗小的微电网系统中,过小的连线阻抗会严重影响功率均分效果甚至会导致系统不稳定。为此设计一种基于虚拟阻抗的"电压–电流"双环下垂控制方法,使并联系统在连线阻抗很小且不对称,传统功率下垂控制方式已不能稳定工作的情况下,仍然能够维持良好的电流均分效果。对比传统三环下垂方法,其具有稳定裕度大,动态响应快,实现简单等特点。最后在理论分析的基础上进行实验研究,通过与三环下垂控制方式的对比,验证了双环下垂控制的有效性。
The three-loop power droop controllers are commonly used in distributed generation （DG） units to share the loads among the parallel inverters. However, the power droop controller is complex and its performance is seriously influenced by the resistance-to-inductance ratio of output impedance. For example, the load sharing performance is very poor under short real line and small impedance especially in microgrid. A simple voltage-current （U-I） dual-loop droop controller based on the virtual impedance was employed to maintain the load sharing capability under small or asymmetry output impedance when the power droop controller was already invalidation. Comparing to the traditional controller, the proposed controller could obtain a faster response, a bigger stability margin and be realized simply. These theoretical findings were eventually verified experimentally on laboratory prototypes.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2011年第33期52-60,共9页
Proceedings of the CSEE
基金
国家自然科学基金项目(50837003
50977081)
河北省高等学校自然科学研究青年基金项目(2011249)~~
